MCQ
If $f(x) = \left\{ {\begin{array}{*{20}{c}}{\frac{{1 - \sin x}}{{\pi - 2x}},}&{x \ne \frac{\pi }{2}}\\{\,\,\,\,\,\,\,\,\,\,\,\,\,\lambda \,,}&{x = \frac{\pi }{2}}\end{array}} \right.$, be continuous at $x = \pi /2,$ then value of $\lambda $ is
  • A
    $-1$
  • B
    $1$
  • $0$
  • D
    $2$

Answer

Correct option: C.
$0$
c
(c) $f(x)$ is continuous at $x = \frac{\pi }{2}$, then

$\mathop {\lim }\limits_{x \to \pi /2} f(x) = f(0)$ or $\lambda = \mathop {\lim }\limits_{x \to \pi /2} \frac{{1 - \sin x}}{{\pi - 2x}}$, $\left( {\frac{0}{0}{\rm{ form}}} \right)$

Applying $L -$ Hospital’s rule,

$\lambda = \mathop {\lim }\limits_{x \to \pi /2} \frac{{ - \cos x}}{{ - 2}}$ 

==> $\lambda = \mathop {\lim }\limits_{x \to \pi /2} \frac{{\cos x}}{2} = 0.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $ \text{x} \in \left ( \frac{3\pi}{2}, 2\pi \right )$ then the value of the expression $ \sin^{-1}[\cos({\cos^{-1}(\cos \, \text{x})}+\sin^{-1}(\sin \, \text{x}))]$ is:
$A (2,6,2), B (-4,0, \lambda), C (2,3,-1)$ and $D (4,5,0)$, $|\lambda| \leq 5$ are the vertices of a quadrilateral $A B C D$. If its area is $18$ square units, then $5-6 \lambda$ is equal to $.........$.
Column-$I$ Column-$II$
$(A)$ In $R ^2$, if the magnitude of the projection vector of the vector $\alpha \hat{i}+\beta \hat{j}$ on $\sqrt{3} \hat{i}+\hat{j}$ is $\sqrt{3}$ and if $\alpha=2+\sqrt{3} \beta$, then possible value(s) of $|\alpha|$ is (are) $(P)$ $1$
$(B)$ Let $a$ and $b$ be real numbers such that the function $f(x)=\left\{\begin{array}{cc}-3 a x^2-2, & x < 1 \\ b x+a^2, & x \geq 1\end{array}\right.$ is differentiable for all $x \in R$. Then possible value(s) of a is (are) $(Q)$ $2$
$(C)$ Let $\omega \neq 1$ be a complex cube root of unity. If $\left(3-3 \omega+2 \omega^2\right)^{4 n+3}$ $+\left(2+3 \omega-3 \omega^2\right)^{4 \omega+3}+\left(-3+2 \omega+3 \omega^2\right)^{4 \omega+3}=0$, then possible value(s) of $n$ is (are) $(R)$ $3$
$(D)$ Let the harmonic mean of two positive real numbers $a$ and $b$ be $4$. If $q$ is a positive real number such that $a, 5, q, b$ is an arithmetic progression, then the value$(s)$ of $|q-a|$ is (are) $(S)$ $4$
  $(T)$ $5$
Side of an equilateral triangle expands at the rate of $2\text{cm}/ \text{sec}.$ The rate of increase of its area when each side is 10cm is:
If the shortest distance between the lines $\frac{x-\lambda}{3}=\frac{y-2}{-1}=\frac{z-1}{1}$ and $\frac{x+2}{-3}=\frac{y+5}{2}=\frac{z-4}{4}$ is $\frac{44}{\sqrt{30}}$, then the largest possible value of $|\lambda|$ is equal to ..........
The general solution of the differential equation $x d y-\left(1+x^2\right) d x=d x$ is :
A curve satisfying the initial condition $y(1)= 0$ satisfies the differential equation $x \frac{dy}{dx}= y -x^2$ the area bounded by the curve and the $x$ -axis is
Let $f:\left[ {4,\infty } \right) \to \left[ {1,\infty } \right)$ be a function defined by $f\left( x \right) = {5^{x\left( {x - 4} \right)}}$  then $f^{-1}(x)$  is
Which of the given value of x and y make the following pair of matrices equal
$\begin{bmatrix}3\text{x}+7&5\\ \text{y}+1&2-3\text{x}\end {bmatrix},\ \begin{bmatrix}0& \text {y}-2\\8&4 \end{bmatrix}$
If A = {1, 2, 3}, B = {1, 4, 6, 9} and R is a relation from A to B defined by 'x is greater than y'. The range of R is: